Recent advances in the synthesis of indolizines and their π-expanded analogues

Sadowski, Bartłomiej,Klajn, Jan,Gryko, Daniel T. The Royal Society of Chemistry 2016 Organic & Biomolecular Chemistry Vol.14 No.33

<P>Indolizine (pyrrolo[1,2-<I>a</I>]pyridine) is one of the five isomers of indole and it serves as a precursor for widespread indolizidine alkaloids. The straightforward synthesis of indolizines based on classical methodologies such as Scholtz or Chichibabin reactions has overshadowed numerous new strategies that have been revealed especially within the last ten years. The desire to achieve substitution patterns which were hard to build sparked the discovery of completely new pathways, <I>e.g.</I> transition metal-catalyzed reactions and approaches based on oxidative coupling. In this review, selected strategies toward indolizines published since 2005 are briefly summarized, commented upon, compared, and illustrated. The literature discussed here involves reactions based on either pyridine or pyrrole scaffolds, as well as selected methodologies leading to π-expanded indolizines.</P> <P>Graphic Abstract</P><P>Synthesis of indolizines developed during the last decade is reviewed, with special emphasis given to densely functionalized architectures, breakthrough strategies, compounds bearing electron-donating and electron-withdrawing substituents and π-expanded systems. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c6ob00985a'> </P>

The influence of tetraphenylethylene moieties on the emissive properties of dipyrrolonaphthyridinediones

Sadowski, Bartłomiej,Su, Shih-Hao,Lin, Ta-Chun,Lohrey, Trevor D.,Deperasiń,ska, Irena,Chou, Pi-Tai,Gryko, Daniel T. The Royal Society of Chemistry 2018 Journal of materials chemistry. C, Materials for o Vol.6 No.45

<P>Despite being highly emissive in solution, aggregation of dipyrrolonaphthyridinedione (DPND) molecules typically results in the quenching of fluorescence. DPNDs can be efficiently converted into π-extended derivatives containing rotatable aryl rings <I>via</I> a direct arylation methodology. The presence of phenyl substituents at positions 3 and 9 of the DPND core is sufficient to cause moderate fluorescence in the solid state. When tetraphenylethylene moieties, typical aggregation induced emitters, are coupled through biaryl linkages in these same positions, a 50 nm shift in absorption and almost 120 nm shift in fluorescence compared to the parent DPND is observed. The radiative S1 → S0 transitions have large oscillator strengths regardless of whether phenyls or tetraphenylethylene groups are coupled to DPND and strong orange or red emission in solution is observed. Vibrations involving these substituents play an important role in the dissipation of the electronic excitation energy. X-ray crystallographic studies revealed that although the distance between DPND cores is strikingly larger in bis(TPE)2DPND compared to that in diphenylDPND, their photophysical properties in the solid state are very similar. Computational studies have also shown that, in contrast to our experimental results, neither of these DPNDs should be particularly emissive in the solid state, due to the low oscillator strengths calculated for model dimers derived from their X-ray crystal structures.</P>

Drug Interactions with Antacids : Mechanisms and Clinical Signigicance

Sadowski, Daniel C. Medical Publications Korea 1995 Medical Progress Vol.17 No.11

Concrete compressive strength prediction using the imperialist competitive algorithm

Łukasz Sadowski,Mehdi Nikoo,Mohammad Nikoo 사단법인 한국계산역학회 2018 Computers and Concrete, An International Journal Vol.22 No.4

In the following paper, a socio-political heuristic search approach, named the imperialist competitive algorithm (ICA) has been used to improve the efficiency of the multi-layer perceptron artificial neural network (ANN) for predicting the compressive strength of concrete. 173 concrete samples have been investigated. For this purpose the values of slump flow, the weight of aggregate and cement, the maximum size of aggregate and the water-cement ratio have been used as the inputs. The compressive strength of concrete has been used as the output in the hybrid ICA-ANN model. Results have been compared with the multiple-linear regression model (MLR), the genetic algorithm (GA) and particle swarm optimization (PSO). The results indicate the superiority and high accuracy of the hybrid ICA-ANN model in predicting the compressive strength of concrete when compared to the other methods.

Structural Genomics of Photosynthetic, Nitrogen-Fixing, Bradyhizobium and Functional Genomics of Bradyhizobium japonicum

Michael Sadowsky 한국응용생명화학회 2008 Applied Biological Chemistry (Appl Biol Chem) Vol.51 No.5

Numerical investigation of the stress field near a crack normal to ceramic–metal interface

Liviu Marsavina,Tomasz Sadowski,Nicolae Faur 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.2

Ceramic–metal interfaces are often present in composite materials. The presence of cracks has a major impact on the reliability of advanced materials, such as fiber or particle reinforced ceramic composites, ceramic interfaces and laminated ceramics. The understanding of the failure mechanisms is very important, as is as the estimation of fracture parameters at the tip of the crack approaching an interface and crack propagation path. A cracked sandwich plate loaded with axial uniform normal stress was numerically investigated using plane strain Finite Element Analysis. The numerical results for the singularity orders were compared with the analytical solution. The influences of the material combination and crack length on the radial and circumferential stresses and displacement distributions were investigated. The Stress Intensity Factors were determined based on numerical results using a displacement extrapolation method. The results for the non-dimensional stress intensity factors show that at lower crack lengths the influence of material mismatch is lower, but this influence increases with increasing crack length.

Interfacial nanostructure induced spin-reorientation transition in Ni/Fe/Ni/W(110)

Lee, J.-S.,Sadowski, J. T.,Jang, H.,Park, J.-H.,Kim, J.-Y.,Hu, J.,Wu, R.,Kao, C.-C. American Physical Society 2011 Physical review. B, Condensed matter and materials Vol.83 No.14

Microbial source tracking using metagenomics and other new technologies

Raza Shahbaz,Kim Jungman,Sadowsky Michael J.,Unno Tatsuya 한국미생물학회 2021 The journal of microbiology Vol.59 No.3

The environment is under siege from a variety of pollution sources. Fecal pollution is especially harmful as it disperses pathogenic bacteria into waterways. Unraveling origins of mixed sources of fecal bacteria is difficult and microbial source tracking (MST) in complex environments is still a daunting task. Despite the challenges, the need for answers far outweighs the difficulties experienced. Advancements in qPCR and next generation sequencing (NGS) technologies have shifted the traditional culture-based MST approaches towards culture independent technologies, where communitybased MST is becoming a method of choice. Metagenomic tools may be useful to overcome some of the limitations of community-based MST methods as they can give deep insight into identifying host specific fecal markers and their association with different environments. Adoption of machine learning (ML) algorithms, along with the metagenomic based MST approaches, will also provide a statistically robust and automated platform. To compliment that, ML-based approaches provide accurate optimization of resources. With the successful application of ML based models in disease prediction, outbreak investigation and medicine prescription, it would be possible that these methods would serve as a better surrogate of traditional MST approaches in future.

Engineering and Manufacturing Technology of Green Epoxy Resin Coatings Modified with Recycled Fine Aggregates

Kamil Krzywiński,Łukasz Sadowski,Damian Stefaniuk,Aleksei Obrosov,Sabine Weiß 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.1

Nowadays, the recycled fine aggregate sourced from construction and demolition waste is not frequently used in manufacturing of epoxy resin coatings. Therefore, the main novelty of the article is to prepare green epoxy resin coatings modified with recycled fine aggregate in a replacement ratio of natural fine aggregate ranged from 20 to 100%. The microstructural properties of the aggregates and epoxy resin were analyzed using micro-computed tomography, scanning electron microscopy and nanoindentation. The macroscopic mechanical properties were examined using pull-off strength tests. The highest improvement of the mechanical properties was observed for epoxy resin coatings modified with 20% of natural fine aggregate and 80% of recycled fine aggregate. It has been found that even 100% of natural fine aggregate can be successfully replaced using the recycled fine aggregate with consequent improvement of the pull-off strength of analyzed epoxy resin coatings. In order to confirm the assumptions resulting from the conducted research, an original analytical and numerical failure model proved the superior behavior of modified coating was developed.

Denitrifying Woodchip Bioreactors: A Microbial Solution for Nitrate in Agricultural Wastewater—A Review

Lee Sua,Cho Min,Sadowsky Michael J.,Jang Jeonghwan 한국미생물학회 2023 The journal of microbiology Vol.61 No.9

Nitrate ( NO3 −) is highly water-soluble and considered to be the main nitrogen pollutants leached from agricultural soils. Its presence in aquatic ecosystems is reported to cause various environmental and public health problems. Bioreactors containing microbes capable of transforming NO3 − have been proposed as a means to remediate contaminated waters. Woodchip bioreactors (WBRs) are continuous flow, reactor systems located below or above ground. Below ground systems are comprised of a trench filled with woodchips, or other support matrices. The nitrate present in agricultural drainage wastewater passing through the bioreactor is converted to harmless dinitrogen gas ( N2) via the action of several bacteria species. The WBR has been suggested as one of the most cost-effective NO3 −-removing strategy among several edge-of-field practices, and has been shown to successfully remove NO3 − in several field studies. NO3 − removal in the WBR primarily occurs via the activity of denitrifying microorganisms via enzymatic reactions sequentially reducing NO3 − to N2. While previous woodchip bioreactor studies have focused extensively on its engineering and hydrological aspects, relatively fewer studies have dealt with the microorganisms playing key roles in the technology. This review discusses NO3 − pollution cases originating from intensive farming practices and N-cycling microbial metabolisms which is one biological solution to remove NO3 − from agricultural wastewater. Moreover, here we review the current knowledge on the physicochemical and operational factors affecting microbial metabolisms resulting in removal of NO3 − in WBR, and perspectives to enhance WBR performance in the future.